PETROLEUM GEOLOGICAL FEATURES AND EXPLORATION POTENTIAL OF THE SERGIPE-ALAGOAS BASIN OF BRAZIL

The Sergipe-Alagoas Basin is an important petroliferous basin in eastern Brazil, and has undergone three tectonic and sedimentary evolution stages. According to the data available, petroleum geological features and the hydrocarbon accumulation model of the basin are comprehensively summarized, and the exploration potential predicted in this paper. ①There are three sets of source rocks developed in the basin, of which the source rocks formed in the transitional period are the most important, followed by that formed in the rift period. The source rock deposited in the drift period is the one with lowest hydrocarbon generation potential. ②There are three sets of reservoirs confirmed in the basin, i.e. the deltaic-aeolian sandstone deposited in the early rift period, the fluvial-deltaic pebbly sandstone or conglomerate in the late rift period, and the sandstone in the drift period. ③Finally, two favorable exploration zones are predicted, which includes the favorable zone of the subsalt rift system in the north of the basin and on the central uplift, and the favorable zone of the drift system in the deep water of the southern part of the Sergipe sub-basin and deep water area outside the Sao Francisco river mouth.